Tag: prominence

I know I’ve posted a lot about the Sun lately, and I knowI just posted a funny picture by astrophotographer Alan Friedman. And maybe I should’ve waited for Caturday to post this. But c’mon. How could I not post this as soon as I saw it?

[Click to concatenate.]

It’s a SOL cat! I love how it looks like it’s rubbing its head on the Sun.

If you want the technical description of what you’re seeing, it’s a solar prominence, a long stream of ionized gas belched out by the Sun, flowing along its magnetic field lines.

Think of it as a 80,000 kilometer-long cosmic hairball the Sun hacked up. I will from now on.

And if you liked that picture by Alan, this one will make your hair stand on end!

[UPDATE: Alan calculated the size of this prominence as 80,000 km, and that looks about right to me. So just for comparison, I added the Earth roughly to scale in the picture here. That’s a pretty big cat. It’s head is bigger than our whole planet! Imagine the litter box that would take…]

But the flares don’t have to be so powerful to generate ethereal, magnificent beauty. A day after that biggish event, those sunspots burped again, this time with a lower-power M-class flare. Now, when I say "low power", it’s not like a firecracker or a car backfiring: the total energy released would still dwarf the combined nuclear might of every country on Earth! By a lot. But for the Sun, that’s considered to be "meh".

Pareidolia is the trait of seeing recognizable objects in random patterns (usually, but not always, faces). Cryptozoology is the study of fabled creatures like Nessie, or the chupracabra, or… I don’t know, for a totally random example, let’s say Bigfoot.

Still not sure what I mean? Maybe this’ll help:

Ha!

OK, I’ll be a pedantic dork for just a sec, and say that this is actually just a prominence, an eruption of ionized gas off the surface of the Sun, guided by the twisting and churning solar magnetic field. Prominences can take all sorts of shapes — even angels and dragons — as they launch upward and fall back down to the Sun’s surface.

Alan Apeman — urp, sorry, I mean Friedman — takes simply amazing pictures of the Sun which I feature here all the time; see the Related posts section below for many more. And you should keep an eye on his pictures. Who knows what you’ll find in them?

He’s still snapping away, and on August 17th took this lovely picture of a prominence erupting from the Sun’s surface:

[Click to enfilamentate.]

Isn’t that gorgeous? A prominence is a towering arc of material lifted off the Sun’s surface by intense magnetic fields. To give you an idea of how strong the magnetic forces are, a prominence can have a mass upwards of a hundred billion tons, and be cranked up thousands of kilometers off the Sun’s surface… despite the crushing gravity of nearly 30 times that of Earth’s!

And some people call the Sun "average". Ha!

Alan takes these images with a pretty nice ‘scope equipped with a filter that blocks all the light from the Sun except for a narrow slice of color preferentially emitted by warm hydrogen. He then inverts the image of the solar disk (but not anything on the limb or outside it), which is an old astronomy trick to make contrast more obvious to the eye.

This image is part of a much larger one showing much more of the solar edge, including another magnificent prominence. Amusingly (to me at least), when I saw the picture above, my first thought is that it looked like a sitting dragon, facing to the right, sniffing a fish floating in front of it (and given that I’m at Dragon*Con right now, I love this imagery even more). Then I realized it also looks like a dragon facing to the left, head down on the Sun’s edge, like it’s ready to pounce! I’d suggest staying out of its way; after all, this dragon would be about 150,000 km long: well over 10 times the size of the Earth.

Do you see it as a dragon too? Funny how once our minds latch onto a picture like that, it’s hard to not see it that way!

Yesterday, "amateur" astronomer César Cantú took an amazing mosaic image of the Sun, showing our star boiling and writhing under its own dynamic forces:

[Click to unGdwarfenate.]

That hardly looks like the Sun, does it? That’s because he used a filter that blocks all the light we see except for a very narrow slice of color in the red part of the spectrum. That filter lets through only light from warm hydrogen, at just the right temperature to allow the electrons in the hydrogen atoms to drop from the third energy level to the second. You can picture the electron in an atom like it’s on a staircase, and only allowed (by quantum mechanics) to sit on a step, or move from one to the other. It takes energy to move it up a step, and gives off energy when it moves down. When it jumps down from the third to the second, it emits a photon — a particle of light — at a wavelength of 656.3 nanometers, and astronomers call this light Hα (H alpha).

The gas on the Sun’s surface emitting Hα is under furious stirring due to magnetic fields and other forces, and you can see that in the twisted, roiling appearance in this photo. I particularly like the dark arc just left of center: that’s a filament, an eruption of gas off the surface. It’s about 150,000 kilometers (90,000 miles) long! It’s a bit cooler than the surface material, so it’s darker, and we see it in silhouette. When those happen on the limb of the Sun they’re called prominences, and you can see several of those in this picture too.

Amazingly, this picture (which is really a mosaic of six separate shots) was taken using a telescope with only a 90 mm (3.5 inch) lens. The Coronado 90 mm telescope is a favorite of sidewalk astronomers, since it shows the Sun in amazing detail, but is totally safe to look through since it blocks almost all the Sun’s light. It’s common to see them at planetaria and museums, set up where passers-by can get a quick glimpse of the Sun. For most, it’s the first time they ever see the might and power of a star only 150 million kilometers away.

And if you want a sense of scale here, in the picture above the Sun is about 450 pixels across. On the same scale, our entire planet Earth would be only about 4 pixels across.

When you build and launch a high-resolution solar observatory that stares at the Sun 24 hours a day, you’re bound to catch some pretty cool stuff. As proof, check out this video of a stunning prominence erupting from the Sun’s surface on July 12, 2011, as seen by NASA’s Solar Dynamics Observatory:

[Make sure you set the resolution to at least 720p.]

That’s really graceful, especially considering that tower reached the staggering height of about 150,000 km (90,000 miles) above the Sun in just a few minutes!

The gas on the Sun is ionized, which means it’s had one or more electrons ripped away from its atoms. Technically called a plasma, this makes it sensitive to the Sun’s strong magnetic forces. That becomes really obvious after it starts to collapse; it doesn’t follow a ballistic trajectory like you’d expect (the path a ball thrown up in the air would follow), but instead flows along the Sun’s magnetic field lines. This video is in the ultraviolet, where such a plasma glows brightly.

For a moment there, just at its peak, it coincidentally looks like a classic angel with wings spread. Of course, once the angel dissolves it forms more of an arc… so I guess this makes it an archangel. I’m glad no one heard a trumpet playing when this happened. That could’ve been awkward.

Scott Wiessinger produces video for NASA’s Goddard Space Flight Center — my old stomping ground, and I did some work with the video folks while I was there, too — and he sent me links to two very cool videos he put together recently.

In early June the Sun erupted, letting loose a huge plume of plasma from its surface which then fell back down along magnetic field lines in a display the likes of which I had never seen before. I created a video (at the link above) which was far and away the most popular I’ve ever done, garnering nearly 1.5 million views as I write this.

Breathtaking, isn’t it? The video is greatly sped up; the whole event took many hours to complete. All the different animations were taken in the ultraviolet, where the highly-energetic plasma erupting from the Sun emits strongly. You can really see that the plasma does not fall along ballistic trajectories (the usual arcs due to gravity) but instead moves along the magnetic field lines, sometimes twisting around in non-intuitive ways. Beautiful, graceful, and stunning.

The second video is from a camera mounted on a sounding rocket, a rocket that goes essentially straight up and back down. At its highest point it goes up nearly 300 km (180 miles), well into space. It was carrying an instrument to observe the Sun in the ultraviolet.

Today, June 21, 2001, at 17:16 UTC (1:16 p.m. Eastern US time), the Sun will reach its peak in its northward travels this year. This moment is the summer solstice — I describe this in detail in an earlier post. Technically, that article is for the winter solstice, but the idea’s the same. Just replace "winter" with "summer" and "December" with "June" and "south" with "north". That should be clear enough. It might be easier just to multiply the entire article by -1. Or stand on your head.

Since for the majority of people on the planet this day marks the start (or more commonly the midpoint) of summer, enjoy the gallery below that shows our nearest star doing what it does best: giving us light, giving us beauty, and sometimes, blowing its top.

Use the thumbnails and arrows to browse, and click on the images to go through to blog posts with more details and descriptions.

NASA’s phenomenal Solar Dynamics Observatory has spent just over a year in space. During that time it has ceaselessly observed the Sun, returning incredibly detailed and exquisite images and videos. In high resolution we’ve seen sunspots, flares, coronal mass ejections, filaments, prominences, and towering loops of magnetic plasma.

To celebrate, the folks at SDO put together this video featuring 12 of their favorite clips. I’ve written about several of these myself in the past year (see Related Posts below). Make sure you set the resolution to 720p!

In a related bit of news, NASA is asking people to vote on their favorite short video from SDO. Many of those clips are also in the above video, but they’re also listed separately on the NASA contest page. I know which one is my favorite… but I’m not telling.

Holy wow! Click to ensolarnate. And I mean it: you want to see the bigger version of this.

This picture was taken by Alan Friedman, who is no stranger to this blog: his picture of the boiling Sun last year was hugely popular, and so amazing I featured it as one of my top pictures of 2010.

And with this he’s done it again… and maybe even topped it.

Alan used a filter that lets through only a very narrow wavelength of light emitted by hydrogen (called Hα for those of you keeping track at home), so this tracks the activity of gas on the solar surface. He also inverts the image of the solar disk (makes it a negative) to increase contrast. Somehow this adds a three-dimensional quality to the picture, and reveals an amazing amount of texture. I swear I had a rug in my bedroom growing up that was this texture (though somewhat cooler and less burny).

The scene-stealer is that detached prominence off to the left. That’s the leftover material ejected from the Sun by an erupting sunspot (you can see other sunspots in the picture as well). The gas is ionized — a plasma — and so it’s affected by magnetic fields. The material follows the magnetic field of the Sun in the explosion, lifting it off the surface and into space. Sometimes it falls back, and sometimes it leaves the Sun entirely. In this case, Alan caught some of the material at what looks like the top of its trajectory.

The beauty of this picture belies its violence and sheer magnitude: the mass of material in a prominence can easily top 10 billion tons! As for size, see that dark elongated sunspot near the base of the prominence, just to the right of the bigger, speckly one? That spot is roughly twice the size of the Earth.

Yegads.

Making this even more amazing, these images are taken with a 90mm telescope — that’s a lens not even 4 inches across! Superior optics, a good mount, and a steady hand can do wonders.

You really need to go and see the rest of Alan’s photography at his site, Averted Imagination. His photos of the skies are surpassingly beautiful.